31521645512 has 48 divisors (see below), whose sum is σ = 68852657520. Its totient is φ = 13489610400.

The previous prime is 31521645511. The next prime is 31521645539. The reversal of 31521645512 is 21554612513.

It is a super-2 number, since 2×31521645512² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31521645511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 212687 + ... + 329057.

It is an arithmetic number, because the mean of its divisors is an integer number (1434430365).

Almost surely, 2^31521645512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31521645512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34426328760).

31521645512 is an abundant number, since it is smaller than the sum of its proper divisors (37331012008).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31521645512 is a wasteful number, since it uses less digits than its factorization.

31521645512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117082 (or 117071 counting only the distinct ones).

The product of its digits is 36000, while the sum is 35.

The spelling of 31521645512 in words is "thirty-one billion, five hundred twenty-one million, six hundred forty-five thousand, five hundred twelve".